             :browsable browsable
             :atom-links atom-links
             :summary summary
+            :metadata-format (name (mt/base-mime-type-to-format format))
             :related-urls (map json/generate-string related-urls)
             :update-time update-time
             :insert-time insert-time

            :coordinate-system (when spatial-representation
                                 (csk/->SCREAMING_SNAKE_CASE_STRING spatial-representation))
            ;; fields added to support keyword searches
            :keyword (k/create-keywords-field concept-id umm-c)
            :long-name.lowercase (when long-name (str/lower-case long-name))
            :platform-ln.lowercase (map str/lower-case platform-long-names)
            :instrument-ln.lowercase (map str/lower-case instrument-long-names)
            :sensor-ln.lowercase (map str/lower-case sensor-long-names)
            :project-ln.lowercase (map str/lower-case project-long-names)
            :temporal-keyword.lowercase (map str/lower-case temporal-keywords)}
           (get-in umm-c [:spatial-coverage :orbit-parameters])
           (spatial->elastic umm-c)
           (sk/science-keywords->facet-fields umm-c))))

(defmethod es/concept->elastic-doc :collection
  [context concept collection]
  (let [{{:keys [short-name version-id entry-id entry-title]} :extra-fields
         :keys [concept-id provider-id native-id revision-date deleted format]} concept
        ;; only used to get default ACLs for tombstones

            :two-d-coord-name.lowercase  (map str/lower-case two-d-coord-names)
            :spatial-keyword spatial-keywords
            :spatial-keyword.lowercase  (map str/lower-case spatial-keywords)
            :attributes (attrib/psas->elastic-docs collection)
            :science-keywords (sk/science-keywords->elastic-doc collection)
            :science-keywords-flat (sk/flatten-science-keywords collection)
            :personnel (json/generate-string personnel)
            :start-date (when start-date (f/unparse (f/formatters :date-time) start-date))
            :end-date (when end-date (f/unparse (f/formatters :date-time) end-date))
